Could the Foot Massage patch be constructed differently?

The circular structure in the picture below is actually laid with odd-shaped stones grouted into the concrete base and is meant for foot massage using the principle of reflexology. But, I am not too sure how effective it is and whether studies have been done to gauge its effectiveness. I suppose the structure is to simulate the bare ground in the olden days, where the ground surface is usually covered with sand, pebbles or smaller-sized stones. When people walk bare-footed on it, the soles actually get massaged by tens of thousands of grains of sands and pebbles. That is the original form of reflexology I think. But, as villages and plantations gave way to modern concrete buildings and constructions, sandy ground patches have become a rare sight.



As for the above construction or similar ones throughout the island, I think the selection of stones and the spacing of the stones layout should be carefully reviewed. If I were to do it, I probably would just spread a couple of layers of COARSE sands instead of using the current stones that are usually quite big in size and the effect of reflexology would be much better felt when you step on the coarse sands. I am speaking from my personal experience of growing up in "kampung" and walking bare-footed on the sandy grounds. I just like that feeling on the soles.